Electrical contacting equipment



2 SHEETS-Sl-IEET 1 mm I I 5 iM M Q Q MQ w m m E 1 9 mn muHr Q Q m 4 flu f/'5 14/. Benbow Jan. 22, 1952 s. w. BENBOW ELECTRICAL CONTACTING EQUIPMENT Original Filed Jan. 31, 1944 Jan. 22, 1952 BY w. BENBOW ELECTRICAL CONTACTING EQUIPMENT 2 Sl-IEETS-SHEET 2 Original Fi led Jan.

4X ommwi W P INVENTOR. Buff/'5 W Benbow 2724, 24m;

A TTOKNE Y5 Patented Jan. 22, 1952 UNITED STATES PATENT OFFICE (CL Mil-23) 3 Claims.

This invention relates generally to electrical equipment of the type making use of a traveling contacting device together with an extended electrical conductor or trolley wire. Such devices can be used advantageously where a trolley arrangement is desired to supply current to movable appliances like hoists and cranes, or even in some instances, portable hand tools. This application is a division of subject matter disclosed in my copending application Serial No. 520,399 filed January 31, 1944, now Patent No. 2,458,778, for Electrical Contacting Equipment."

It is a general object of the invention to provide improved electrical equipment of the above character, and in particular to improve upon equipment of the type disclosed and claimed in ngy4 Patent No. 2,255,874 granted September 16, 1 1.

Another object of the invention is to provide an improved form of sheath for the wire or conductor, which is formed of resilient insulating material, and which. has a novel construction to facilitate application of the same about a trolley wire.

Another object of the invention is to provide a novel. assembly comprising my insulating sheath together with mounting means for the some, the mounting means serving to maintain the sheath upon the trolley wire.

Additional objects of the invention will appear from the following description in which the preferred embodiments of the invention have been set forth indetail in conjunction with the accompanying drawing.

Referring to the drawing:

Figure l is a side elevational view partly in section showing electrical equipment incorporating my invention.

Figure 2 is a sectional view taken along the line 2'--2 of Figure 1 showing the electrical conductor and its insulating sheath, and the mounting means therefor.

Figure 3 is a cross-sectional view of my electrical conductor and its insulating sheath.

Figure 4 is a cross-sectional view taken along the plane 4-4 of Figure 1 showing my traveling electrical contac'tor in cooperative relation with the electrical conductor and its mounting means.

Figure 5 is a cross-sectional view taken along line 5--5 of Figure 1.

Figure 6 is a cross-sectional detail taken along the line 6-4; of Figure 1 Figure 7 is a three-quarter side elevational view showing one of the two has bar elements of my traveling electrical o'ontaotor;

The equipment illustrated in the drawing incorporates the invention disclosed and claimed in my aforesaid- Patent No. 2,255,874. However improved features are included as will be hereinafter disclosed.

In general the apparatus consists of an electrical conductor or trolley wire If! which is enclosed by the insulating sheath H, and which cooperates with the special traveling electrical contacting device l2. While the insulating sheath ii can be made of various materials, it is preferably formed of molded resilient material, such as natural or synthetic rubber. A sheath of the type illustrated and a novel method for its manufactors have been disclosed and claimed in my oo-pending application Serial No. 769,001, filed August 16, 194'? and entitled Molding Machine and Method, now Patent No. 2,532,080, dated November 28, 1950. This sheath is preferably formed of the two side body portions Ha and 1 lb, (Figure 3), which have a longitudinal cavity Hi to receive a trolley conductor, and which are joined together by the spaced integral ribs Hi. When viewed in section as in Figure l the end faces of these ribs are curved like the faces of epicyclic spur gear rack teeth.

To form my sheath I preferably make use of the molding machine and method disclosed in my aforesaid application Serial No. 769,001. However immediately upon withdrawal of the molded sheath from the machine, the back side of the body is split to the recess l3, as shown in Figure 3, and the wire utilized for forming the recess I3 is then withdrawn. It will be evident that a sheath of this sort can be readily applied over a trolley wire simply by pulling the body portions Ha and I lb apart, and forcing the same over the wire. A trolley wire enclosed in such a sheath is completely insulated against accldental contact, and the wire is only exposed for electrical contact through the openings l5 between the teeth H. To facilitate retention of the sheath within the novel mounting to be presently described, the body portions llaand Nb are preferably provided with longitudinally extending ridges or ribs Hi.

The novel mounting means illustrated consists of a pair of retention strips H, which can conveniently be formed of pressed sheet metal bent angle shaped as illustrated. The base portions' of these strips are provided with turned edges I8. to engage about the longitudinal ridges IS. The adjacent wall portions [9 are preferably shaped substantially as illustrated (Figure 2) whereby when these portions are urged together the turned edge portions l8 are forced into tight engagement with the ribs l6. Thus the two body portions I la and Nb of this sheath are pressed together about the trolley wire, while at the same time the sheath together with the enclosed cable are adequately held by the strips IT. The complete assembly of strips forms in effect a metal mounting which is substantially T shaped in cross section.

In order to retain the strips I! together and at the same time to support the assembly upon the structural members of a roof or ceiling, I have provided suitable brackets 20 which can be in the form of a depending sheet metal plate. The lower portion of this plate is slit (Figure 1) to provide spring tabs 2| and 22, which are bent to clip over the adjacent wall portions IQ of the strips 47 (Figure 6). Thus strips H are held tightly together while at the same time these strips are adequately supported from a series of brackets 23. As will be presently explained when the assembly is supported in this manner the base portions of the strips l1 form trackways for wheels, which in turn serve to support the traveling contacting device.

The traveling electrical contacting device I2 is similar to that disclosed in my aforesaid copending application in that it employs a series of teeth-like conductor elements 30 which are connected together by suitable links 3|, to form an endless chain. This chain-like assembly is trained about a pair of pulley wheels 32, which can be made of suitable insulating material, and which can be provided with suitable bearings 33 on the shafts 34. The pulleys and the associated parts of the contactor device are enclosed within a suitable housing 35 formed of suitable insulating material such as a molded phenolic condensate product. Preferably this housing is formed as two halves 35a and 35b, which are detachably retained together by being bolted to the ends of the shafts 34 (Figure 5).

In order to properly support the contacting device relative to the trolley wire and sheath, the housing carries upwardly extending members 36 and 31 which in turn carry the flanged wheels 38and 39. These wheels are adapted to track upon the base portions of the strips substantially as shown in Figure 4.

The end faces of a number of the teeth 30 normally engage and make electrical contact with the trolley wire I0, as shown in Figure 1. The base portions 301) of the teeth 30 are arranged to slide over and make electrical engagement with the bus bars 4|. These bus bars are yieldably mounted within the housing 35 by novel means, whereby they are relatively uniformly and yieldably pressed against the base portions 301) of the teeth, to provide good electrical contact at all times without arcing. Thus medial portions of both bars are pivotally connected by pins 42 with the oppositely extending arms 43 of the L levers 44. L levers 44 are pivotally carried by common pin 45, and are urged in opposite directions by the compression spring 46. Thus each of the bus bars 4| is yieldably urged upwardly against the base portions 30b of the teeth 30, and in addition each bus bar is free to rock about the axis of its pivot pin 42. The end extremities 41 of the bus bars are preferably tapered and reduced in width, in order that they may be loosely accommodated within the grooves of wheels 32.

Below the pivot pins 42 both bus conductors 4| are connected by the flexible stranded conductors 48 to the terminal strip 49. This strip in turn is shown connected to the terminal fitting 5| of the insulated conductor 52. It is this conductor which leads the current to the appliance being operated.

In order to minimize friction between the bus bars 4| and the teeth 30, the upper faces of the bus bars can be provided with cavities 53 (Figure 7) which can be filled with graphite or a like lubricating medium.

In order to facilitate traversing of the contacting device along the trolley wire, I can provide suitable means such as a bail 54 which can be pivotally attached to the ends of one of the shafts 34, and which in turn can connect to any suitable contrivance, such as the pull rod 56.

iii)

Operation of the equipment described above can be briefly outlined as follows: The assembly including the insulating sheath and the strips i7 is mounted in the position desired, and supported by the brackets 20. The contacting device i2 is tracked upon this assembly, with the wheels 38 and 39 engaging the base portions of the strips i'l, substantially as shown in Figures 1 and 4. The upper rod of the endless contacting chain is disposed with its teeth entering the openings l5, substantially as shown in Figure l, and with the end faces 30a of the teeth being pressed upon the exposed portions of the trolley wire. As shown in Figure 4 it is desirable that these end faces of the teeth 38 be provided with a substantially V-shaped groove in order to more adequately seat and center the same with respect to the trolley wire. In the device illustrated in the drawing a minimum of at least five teeth 30 are in continuous contact with the trolley wire. Furthermore all of these teeth are being yieldably urged against the trolley wire by the bus bars 4|.

It will be noted in Figure 1 that the length of each opening I5 between the formed insulating teeth or ribs I4, is considerably greater than the length of the formed teeth 30. Also it will be noted that the tooth near the left hand end of Figure 1, which is about to be retracted from its associated opening l5, has its curved trailing face in abutting contact with the adjacent curved leading face of a rib l4. On the other hand the tooth appearing near the right hand end of Figure 4, which has just been advanced into its associated opening l5 to bear upon the trolley wire, has considerable clearance between both its leading and trailing faces and the adjacent faces of the teeth |4 preceding and behind the same. Between the two teeth 30 just mentioned, the intervening teeth appear in various intermediate positions, indicating that there is a substantial sliding movement between each tooth and the trolley wire, commencing with the instant the tooth engages the trolley wire, and ending with retraction. Such sliding movement makes for good electrical contact between the teeth and the conductor.

It will be evident from the above that my equipment is capable of application to a wide variety of services, including the various services where it is now common to make use of conventional exposed trolley wires, with conventional sliding shoes or trolley wheels. Relatively heavy currents can be taken off through my contacting devicewithout arcing and without wear or pitting of the trolley wire. In general all parts of my equipment have a long useful life without undue wear, and thus expensive servicing such as is common with conventional arrangements, is reduced to a minimum. The work of installing the equipment is reduced to a minimum because 0! the simple and novelcharacter of the insulating sheath and its mounting.

I claim: 1

1. In equipment of the character described, a sheath for a wire or conductor comprising an extended integral body formed of resilient insulating material, said body being formed to provide a cavity extending -;'longitudinally through the same to receive a trolley wire and also formed to provide a seriesqij; spaced openings through one side of the sheath, the openings being formed between a series of spaced teeth formed integrally with the body, that side of the body opposite the teeth being provided with a longitudinal slit whereby the body can be distorted for application about a trolley wire.

2. In apparatus of the character described, an extended trolley wire, a sheath embracing the trolley wire, the sheath having a series of downwardly extending openings through which the lower side of the trolley wire can be engaged, the sheath also having a'siit extending longitudinally of the same and downwardly from the upper face of the sheath and having a pair of ridges formed along the sides of the sheath adjacent the upper sheath face,,all portions of the sheath being formed integral and of resilient insulating material, and a mounting means for the sheath, said mounting means including portions engaging said ridges and engaging the sides of the sheath adjacent the upper sheath face and serving to clamp the two side portions of the sheath together.

3. In apparatus of the character described, an extended trolley wire, a sheath embracing the trolley wire, the sheath having a series of downwardly extending openings through which the lower side of the trolley wire can be engaged, the sheath also having a slit extending longitudinally of the same and downwardly from the upper face of the sheath, all portions 01' the sheath being formed integral and of resilient insulating material, and mounting means for the sheath, said mounting means including portions engaging the sides of the sheath and serving to clamp the two side portions of the sheath together.

BURTIS WILLIAM BENBOW.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 645,615 Wright Mar. 20, 1900 2,255,874 Benbow Sept. 16, 1941 

